Serverless Computing on Azure Functions and Webhooks (.NET 6.0)

Serverless Computing is Platform as a Service (PaaS) in Cloud Services. It allows us to deploy and manage individual code functions without a need to deploy and manage on the individual Virtual Machine (VM). Azure Functions is a serverless compute service that runs our code on-demand without needing to host it on the server and managing infrastructure. Azure Functions can be trigger by a variety of events. It allows us to write code in various languages, such as C#, F#, Node.js, Java, or PHP.

• What is Webhooks?
• Implementation of Azure Functions using HTTP Trigger
• How to Create Function App in Azure portal, Visual Studio, VS code.

Glimpse of Post

Prerequisite

• Beginner level knowledge of Microsoft Azure
• Azure portal Account & Subscription
• Visual Studio or VS code
• .NET SDK
• C# Extension for VS code

What is Webhooks?

• Webhooks are user-defined HTTP callbacks. They’re triggered by some event, such as pushing code to a repo or updating a wiki page.
• When the event occurs, the source site makes an HTTP request to the URL configured for the webhook.
• With Azure Functions, we can define logic in a function that can be run when a webhook message is received.
• One common use of webhooks in a DevOps environment is to notify an Azure function that the code or configuration for an application has changed in GitHub.
• The payload of the message sent through the webhook contains the details of the event.
• You can use the webhook with a function to perform a task such as deploying the updated version of the application.

How can we create Azure Functions in Azure portal?

• Sign in Azure portal account, if you don’t have account, you can create Trial or free account through https://portal.azure.com/
• Under App Services, Select Create Resource and then Choose Function App Create option.

• Under Basics, you have to Select Subscription and Resource group from the dropdown list or you can create new Resource group.
• Then, Function App name should be Globally unique with no case sensitive.
• Publish, what publishing type want to publish here we select code.
• Runtime stack and version is to build functions on which language or platform, here we select .Net and version 6.0
• Select your Region, deploying Operating system.
• Select Plan Type as Consumption (Serverless) from options.
• Click Next: Hosting

• Select Storage account or create new storage account to host the u.
• Click Monitoring.

• If you build a function app for production level, then you should enable application Insights, For testing no need to enable app sights, here we select No.
• Review Details given under Review + create tab and click create

• Wait for couple of minutes, Deployment is in process. After deployment is successful Click Go to Resource.
• Click Functions from left launch bar and then click Create to Create function
• Select Development Environment as Develop in Portal and give new function name and Authorization level.

• For testing select authorization level as Anonymous, Click Create.
• Now your function created in your created Function app.
• Click Function, In Left launch menu click Code + test.

• Click Get Function URL, then copy to clipboard option to copy the app publishing url.
• Open new tab and paste the URL and followed by url ?name=your name, once you press enter the function trigger the HTTP trigger (GET and POST) event.
• If you gave Authorization level as Function, you need to give &name= your name.
• You can see the logs of result executing in Logs section.
• We successfully built and ran a functions using function app in Azure Portal

Build Functions in Visual Studio:

• You should have azure packages in visual studio, To install the Azure package open the visual studio installer and install the Azure cloud platform.
• After installing, select create new project and search as Azure you will find the Azure Functions. Click Next.

• In Next Page, you have to give Name for the Project and as well as Solution. Then click Create.
• Visual studio scaffolds the functions for our function app.

using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;

namespace HttpTriggerFunctionApp
{
    public static class Function1
    {
        [FunctionName("Function1")]
        public static async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
            ILogger log)
        {
            log.LogInformation("C# HTTP trigger function processed a request.");

            string name = req.Query["name"];

            string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
            dynamic data = JsonConvert.DeserializeObject(requestBody);
            name = name ?? data?.name;

            string responseMessage = string.IsNullOrEmpty(name)
                ? "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response."
                : $"Hello, {name}. This HTTP triggered function executed successfully.";

            return new OkObjectResult(responseMessage);
        }
    }
}

• In Function.cs, you can see the Authorization Level and Request Methods with the Routing of HTTP Trigger method, so it can perform GET and POST methods.
• Which you return the data is return as a response by Function (which the implementation is a Event).
• Run the function app by pressing F5, if you need to debugging then press ctrl + F5.

• Your function app will logs the functions status and details in command prompt, if there any updated.
• It shows the localhost port number and URL.
• Copy the URL and hit Enter. It will hit the debugger and we can see the name as given name (?name=__)

• Click Continue to see the output result, it will give the response body as what we returned with given name.
• You successfully ran the Serverless computing using Azure functions in Visual Studio.

Build Functions in VS code:

• To run Azure function in VS code install Azure Function or Azure Tools Extension by Microsoft.
• Click Azure Icon on Launch Tab and then Expand Workspace -> click + -> create Resource.

{
  "profiles": {
    "Functions": {
      "commandName": "Project",
      "commandLineArgs": "--port 7131",
      "launchBrowser": false
    }
  }
}

• Basics Detail Pane will appear, Function app name, Subscription, Resource group, Platform, Version, Plan Type, Authorization Level all the details have to filled in prompt field.
• At Finally Your Function app is ready to use Function app.
• In launchSettings.json you can get the application localhost port number.
• Cli to run function app => Azure Functions: Execute function now in terminal (or) press F5 (or) go to Run -> Run without debugging
  • Note : You must have .NET SDK and runtime tools and C# extension in VS code.
• Now, you can see the response body sent by the function app.

Conclusion

• Hope, You Learnt about Serverless computing, Azure Functions and Webhooks. Share to other people to know about Serverless computing using functions.

Next post will Concentrate on Azure Core Concepts and Services.

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